03 October 2026

Using Pearls in a Choose Your Own Adventure game

I had an idea for a game about how human organisations - like Governments or Tech Companies - might address the possible rise of an AI Superintelligence. This was inspired by the book "If anyone builds it, everyone dies" and the report "AI 2027".

I put forward my hastily put together ideas at a CLWG online design session.

My initial game concept was to use a script of the AI threat. The script would be presented to the players as a cut-scene, followed at the end with a series of prescribed choices. I likened this to "Choose Your Own Adventure (CYOA)".

In the design session I was cautioned about the wisdom of using CYOA. Too many options leading to too many possible outcomes that the designer gets lost or confused in writing lots of unlikely outcomes - known as Combinatorial Explosion. This is indeed a nasty little problem.

Taming Combinatorial Explosion

After the session I dipped Jesse Schell's "The Art of Game Design". It too made those wise criticisms of CYOA.

Schell makes the point that there only two successful ways of implementing story or narrative in games - The String of Pearls and the Story Machine. All other methods usually fail. (see p. 318-319). 

The String of Pearls method is a linear storyline. The "string" is a cut-scene setting out the motivation for the player actions. The pearls are the action scenes whereby the player defeats the obstacle, enemy and then moves to the next cut-scene. Story Machines are complex open ended games like Sims or Minecraft, that rely on emergent narratives.

Hill 70 and Containing Combinatorial Explosion in a Pearl

After reading Schell I thought about the one CYOA game I had made using Twine - Hill 70. I realised that I had used the String of Pearls approach to my CYOA.  

The String in Hill 70 were the Infantry Unit's orders and its situation. They were going to be ordered to the front line. 

Inside each Pearl the player made some choices about how to move their infantry unit in accordance to its orders. There was no choice about leaving the mission or deviating. They followed orders. The choices I presented the player were the choices a Commander of an Infantry Battalion would reasonably have. For example, did he order "coffee and hot bread rolls" to be served to the troops standing on alert? What formation did the unit use to advance in under artillery fire?

I had not realised that I had done that. In my analysis I identified three pearls - stand-to, move up to the front, in the front line.

AquaLuft's String of Pearls Approach to CYOA

After a little more searching, I discovered another game designer - the wonderfully named AquaLuft - had also implemented the same solution.


https://aqualuft.wordpress.com/2014/01/08/queen-at-arms/

"[The game] Queen At Arms follows the “string of pearls” method of interactive fiction, where a linear sequence of complex scenes are strung into a narrative. Each scene is an explosion of choice, that boils down into a handful of outcomes and set flags that are then referenced in further scenes. This is the most efficient method for creating a sense of player agency and real consequences, while still being reasonable to develop."

Conclusion

I wonder if I might go back to the CYOA approach for my "If anyone builds it" game. Using the String of Pearls to contain too much choice. I need to map out each of the Pearls. I need to decide what player options there are in each Pearl so I can then judge how well the players have done, and then move along the string to the next Pearl.

In Twine - the computer game engine I used for Hill 70 - I had used variables to change the paths presented at the end of each Pearl. For example if the players had not looked after their men and had taken too many casualties and exhausted them they did not get the final "hurrah, charge" ending. 

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